Magnetic coupler for hemostatic rotor sealing

Abstract

Devices and methods for assisting blood flow are provided. The device includes a housing with an inlet and an outlet, and a fluid barrier separating the housing into a first section containing the inlet and outlet, and a second section. The device also includes an impeller shaft coupled to an impeller and a first magnet in the first section of the housing, and a drive shaft coupled to a second magnet in the second section of the housing. The first and second magnets are arranged such that rotation of the drive shaft rotates the second magnet causing rotation of the first magnet, which drives the impeller.

The invention claimed is: 
     
       1. A medical device for placement within a heart of a patient, the medical device comprising:
 a housing including an inlet for receiving blood flow and an outlet for delivering blood flow; 
 a fluid barrier disposed within the housing, the fluid barrier including a round opening, and the fluid barrier being impervious to fluid and separating the housing into a first section containing the inlet and the outlet, and a second section; 
 an impeller shaft disposed within the first section of the housing; 
 an impeller disposed within the first section of the housing and coupled to the impeller shaft; 
 a first magnet disposed in the first section of the housing and coupled to the impeller shaft; 
 a drive shaft disposed within the second section of the housing; 
 a second magnet disposed within the second section of the housing, the second magnet being rotatably coupled to and translatable along the drive shaft, the second magnet including a non-round opening; and 
 a pivot member disposed between the second magnet and the fluid barrier, the pivot member having a non-round proximal protrusion engaging the non-round opening of the second magnet such that rotation of the drive shaft and the second magnet relative to the housing causes rotation of the pivot member relative to the housing, and the pivot member further including a round distal protrusion engaging the round opening of the fluid barrier such that the pivot member is rotatable against the fluid barrier; 
 wherein rotation of the drive shaft and the second magnet relative to the housing causes the first magnet, the impeller shaft, and the impeller to rotate relative to the housing. 
 
     
     
       2. The medical device of  claim 1 , further comprising a power source operably coupled to the drive shaft. 
     
     
       3. The medical device of  claim 2 , wherein the power source is a motor. 
     
     
       4. The medical device of  claim 1 , wherein a proximal end of the impeller shaft extends proximal of the first magnet, the proximal end having a first protrusion configured to be received by a first recess in the fluid barrier. 
     
     
       5. The medical device of  claim 4 , wherein the impeller shaft includes a disc adjacent the first protrusion, the disc extending perpendicularly from a longitudinal axis of the impeller shaft. 
     
     
       6. The medical device of  claim 5 , wherein the disc has two opposing lobes. 
     
     
       7. The medical device of  claim 1 , further comprising a bearing assembly supporting and centering a distal end of the impeller shaft, the bearing assembly including a bearing housing fixed to the housing, a spacer slidably disposed within the bearing housing, and a distal bearing fixed within the spacer. 
     
     
       8. The medical device of  claim 7 , wherein the bearing assembly further includes a spring member disposed around the spacer. 
     
     
       9. The medical device of  claim 1 , wherein the fluid barrier acts as a thrust bearing against which the pivot member is rotatable.